Germanium tetrafluoride
Germanium tetrafluoride (GeF4) is a chemical compound of germanium and fluorine. It is a colorless gas.
Names | |
---|---|
IUPAC names
Germanium tetrafluoride Tetrafluorogermane Tetrafluoridogermanium | |
Other names
Germanium(IV) fluoride Germanium fluoride | |
Identifiers | |
3D model (JSmol) |
|
ChemSpider | |
ECHA InfoCard | 100.029.101 |
EC Number |
|
PubChem CID |
|
UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
Properties[1] | |
GeF4 | |
Molar mass | 148.634 g/mol |
Appearance | colourless gas |
Density | 6.074 g/L (gas), 2.46 g/mL (liquid)[2] |
Melting point | −15 °C (5 °F; 258 K) at 4 bar |
Boiling point | −36.5 °C (−33.7 °F; 236.7 K) sublimates |
−50.0·10−6 cm3/mol | |
Structure | |
tetrahedral | |
Thermochemistry | |
Std enthalpy of formation (ΔfH⦵298) |
-8.008 kJ/g |
Hazards | |
Main hazards | Reacts with water to form HF, corrosive |
R-phrases (outdated) | R26 R35 |
S-phrases (outdated) | S9 S26 S28 S36 S45 |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Related compounds | |
Other anions |
Germanium tetrachloride Germanium tetrabromide Germanium tetraiodide |
Other cations |
Carbon tetrafluoride Silicon tetrafluoride Tin tetrafluoride Lead tetrafluoride |
Related compounds |
Germanium difluoride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Infobox references | |
Synthesis
Germanium tetrafluoride is formed by treating germanium with fluorine:
- Ge + 2 F2 → GeF4
Alternatively germanium dioxide combines with hydrofluoric acid (HF):[3]
- GeO2 + 4 HF → GeF4 + 2 H2O
It is also formed during the thermal decomposition of a complex salt, Ba[GeF6]:[4]
- Ba(GeF6) → GeF4 + BaF2
Properties
Germanium tetrafluoride is a noncombustible, strongly fuming gas with a garlic-like odor. It reacts with water to form hydrofluoric acid and germanium dioxide. Decomposition occurs above 1000 °C.[5]
Reaction of GeF4 with fluoride sources produces GeF5− anions with octahedral coordination around Ge atom due to polymerization.[6] The structural characterization of a discrete trigonal bipyramidal GeF5− anion was achieved by a "naked" fluoride reagent 1,3-bis(2,6-diisopropylphenyl)imidazolium fluoride.[7]
Uses
In combination with disilane, germanium tetrafluoride is used for in the synthesis of SiGe.[2]
References
- Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. p. 4.64. ISBN 0-8493-0486-5.
- Germanium(IV) fluoride. sigmaaldrich.com
- Greenwood, N. N.; Earnshaw, A. (1998). Chemistry of the Elements (second edition). Butterworth Heinemann. pp. 376–377. ISBN 0-7506-3365-4.
- Georg Brauer: Handbuch der Präparativen Anorganischen Chemie
- Germaniumtetrafluorid. IFA Database
- Mallouk, T. E.; Desbat, B.; Bartlett, N. (1984). "Structural Studies of salts of cis and trans μ-Fluoro-Bridged Polymers of Pentafluorogermanate(1-) and of the Pentafluorogermanate(1-) Monomer". Inorganic Chemistry. 23: 3160-3166. doi:10.1021/ic00188a027.
- Alič, B.; Tramšek, M.; Kokalj, A.; Tavčar, G. (2017). "Discrete GeF5– Anion Structurally Characterized with a Readily Synthesized Imidazolium Based Naked Fluoride Reagent". Inorganic Chemistry. 56: 10070-10077. doi:10.1021/acs.inorgchem.7b01606.